BOSTON -- Gov. Deval Patrick on Tuesday will begin to put this summer’s broad debate over transportation infrastructure and taxes into more concrete terms, announcing plans for the state to invest in three major projects that include the purchase of more than 225 new subway cars and the imminent start of electronic tolling.

The third project set to start immediately will be the reconstruction of the turnpike in Allston to straighten the highway and eliminate curves before and after the tollbooths to reduce congestion, ease traffic flow and free up 60 acres of land for development in the Beacon Yards area, according to a senior administration official.

Patrick, who is due to deliver a speech to the Greater Boston Chamber of Commerce on Tuesday morning, will highlight the transportation investments as part of the administration’s broader strategy, approaching his final year in office, to lay the groundwork for projects he hopes will pay dividends on economic growth for years to come.

The governor plans to makes a series of speeches in the coming weeks at regional chambers of commerce where he will roll out regional investments around the state in transportation, as well as the education and innovation sectors. Last week in Salem, Patrick announced $53.6 million for new classrooms, lab space and student facilities at Salem State University and North Shore Community College.

After the bruising tax debate over the first seven months of the year, Patrick’s focus has shifted largely to managing the expansive state government apparatus, rather than pushing new legislative goals. Electronic tolling and the purchase of new subway cars are not new ideas from the governor, and were included in the “Way Forward” capital plan published in January.

A senior administration official said Patrick’s remarks Tuesday will key off his recurring theme of “generational responsibility” and the importance of making the investments now that will unlock business growth and prepare students and entrepreneurs for the future economy.

With the administration planning to publish an updated capital plan in the coming weeks based on the $600 million to $800 million in new annual revenue earmarked for transportation by this summer’s tax bill, Patrick will discuss the importance of continuing to pursue reform and efficiency, ensuring regional equity and making sure projects like South Coast rail and the Green Line extension progress to guarantee the transportation system has the capacity to meet future rider demand.

Because Patrick did not get the full revenue package he pushed for in January, the administration has said it will have to prioritize projects in its capital plan knowing that any project not started or delayed until after December 2014 will become subject to the fancy of the next governor.

Patrick plans to announce that on Tuesday the MBTA will issue a $1.3 billion request for proposals to purchase new Red and Orange Line cars to replace subway cars built in the late 1960s and early 1980s respectively. The MBTA plans to award a contract by next winter to purchase 152 new Orange Line cars to replace the entire fleet and 74 new Red Line cars, transitioning out one-third of the Red Line cars currently on the tracks.

“These should have been sent to the transportation graveyard 10 or 15 years ago, but we haven’t been able to do it,” said Transportation Secretary Richard Davey, explaining that the MBTA should be running 102 Orange Line cars a day to serve the volume of riders, but has been limited to less than 96 a day because of the aging fleet in constant need of repairs.

Because the MBTA will not be relying on federal funds to replace the T cars, the administration can and will insist in the bids that the cars be assembled in Massachusetts, Davey said. The new cars will cost about $800 million, and the remainder of the money will to be used for upgraded power and signal systems. The full replacement could take eight to nine years, according to Davey, with Orange Line cars starting to arrive in the winter of 2018 and Red Line cars following in 2019.

The move to electronic, or open-road, tolling, will begin with the inbound Tobin Bridge tolls over the Mystic River between Chelsea and Charlestown. Davey said the electronic tolling system will be up and running by January for a four-to-eight week test phase. The system will go live by March and demolition of the toll booths will begin thereafter.

Though MassDOT has been making an effort to sign up drivers for E-ZPass transponders that will be compatible with the new system, the license plates of drivers without transponders will be photographed and bills sent to the address corresponding to the vehicle’s plate.

After the Tobin Bridge system is operational, Davey said, MassDOT will move on to the Boston Harbor tunnel tolls and the Mass. Turnpike itself, a project that will start next summer and could run into late 2015 or early 2016, long after Patrick leaves office.

“We have no doubt it’s going to work. It works in other states,” Davey said. The administration anticipates the $100 million installation cost will pay for itself over three years with the eliminated expense of manual toll collection, which costs $45 million to $55 million a year.

The roughly 20 Tobin bridge toll collectors will be absorbed into the system for now, according to Davey, but the administration is working with the Teamsters union to assist the 410 full- and part-time toll collectors whose jobs will be eliminated within three years. The cost of the new tolling system will be paid with toll revenues.

The Allston Turnpike project will cost an estimated $260 million, with construction scheduled to start in the fall of 2016 and be completed in 2020. Patrick will also announce plans to replace the Clayton Street Bridge in Dorchester over Veterans Day weekend as part of the “Fast 14” program.

“These are the kinds of things we think can improve the experience for a number of folks. We’re prioritizing what is needed and what will effect the greatest number of people,” Davey said.